Friday, January 16, 2015

Mysterious Antikythera Mechanism Is Even Older Than We Thought

The 82 discolored, corroded bronze fragments of the Antikythera Mechanism may not look like much on their own. But assembled they reveal a complex mechanism, with 37 gears that track the sun and moon and predict eclipses. This astronomical calendar or calculator was discovered in a shipwreck off the coast of Crete in 1901 and is more than 2,000 years old.

This ancient device "predates other known examples of similar technology by more than 1,000 years," writes John Markoff for the New York Times. He says:

Archaeologists and historians have long debated where the device was built, and by whom. Given its sophistication, some experts believe it must have been influenced, at least, by one of a small pantheon of legendary Greek scientists — perhaps Archimedes, Hipparchus or Posidonius.

Now a science historian and a physicist have discovered one more clue about the device’s origin. The eclipse prediction calendar, a dial on the back of the mechanism includes a solar eclipse that happened May 12, 205 B.C. They published their findings in the Archive for History of Exact Sciences.

Researchers had previously subjected the mechanism to radiocarbon dating analysis and analyzed the Greek letters inscribed on the front and back to come up with a construction date of about 100 to 150 B.C., reports Ker Than for LiveScience. The new date pushes the origin back 50 years or even a century, Markoff writes, and indicates that the math the mechanism uses to predict eclipses is Babylonian arithmetic, not Greek trigonometry.

Archimedes probably wasn’t the creator: he made his home in Syracuse, where earlier analysis of the mechanism's inscriptions suggested it might have been made. But the device also includes an inscription that refers to an athletic competition held in Rhodes, the likely place of origin, experts told the Times.

The mechanism remains intriguing because regardless of the exact date of its creation, it was centuries ahead of its time. LiveScience's Than writes:

Previous reconstructions suggested the Antikythera Mechanism was about the size of a shoebox, with dials on the outside and a complex assembly of bronze gear wheels within. By winding a knob on its side, the positions of the sun, moon, Mercury and Venus could be determined for any chosen date. Newly revealed inscriptions also appear to confirm previous speculations that the device could also calculate the positions of Mars, Jupiter and Saturn — the other planets known at the time.

Earlier this fall, an expedition returned to the site of the shipwreck—with the aid of "wearable submarine" suits—and brought back tableware, parts of the ship and a bronze spear. They plan to dive again in the spring. Findings from that trip may reveal more about this strangely advanced device.
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Fessenden, Marissa. 2015. “Mysterious Antikythera Mechanism Is Even Older Than We Thought”. Smithsonian Magazine. Posted: November 26, 2014. Available online: http://www.smithsonianmag.com/smart-news/ancient-astronomical-calculator-even-older-we-thought-180953472/?no-ist

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